diff --git a/func/Module_cut_pair_file.py b/func/Module_cut_pair_file.py
index 9d6f25b..ee92f51 100644
--- a/func/Module_cut_pair_file.py
+++ b/func/Module_cut_pair_file.py
@@ -438,19 +438,18 @@ class Data:
 
             # 如果pos<0，表示BCG信号比ECG信号提前，需要在开头去除掉一部分BCG信号
             if pos < 0:
-                front_BCG = ceil(-pos) + OrgBCGShift
+                front_BCG = ceil(-pos) - OrgBCGShift
                 front_ECG = 0
             else:
-                front_BCG = 0 + OrgBCGShift
-                front_ECG = ceil(pos)
+                front_BCG = 0
+                front_ECG = ceil(pos) + OrgBCGShift
 
-            # 计算结束位置
-            if (BCG_second - front_BCG) > (ECG_second - front_ECG):
-                back_ECG = ECG_second + front_ECG - 1
-                back_BCG = back_ECG - ceil(pos)
-            else:
-                back_BCG = BCG_second + front_BCG - 1
-                back_ECG = back_BCG + ceil(pos)
+            # 计算剩余长度
+            remain_BCG_second = BCG_second - front_BCG
+            remain_ECG_second = ECG_second - front_ECG
+            remain_second = min(remain_BCG_second, remain_ECG_second)
+            back_BCG = front_BCG + remain_second - 1
+            back_ECG = front_ECG + remain_second - 1
 
             self.alignInfo = {
                 "cut_index": {